This application relates generally to inspecting objects, and more specifically to methods and apparatus for inspecting objects using a light measurement system.
Objects are sometimes inspected, for example, to determine a size and/or shape of all or a portion of the object and/or to detect defects in the object. For example, some gas turbine engine components, such as turbine or compressor blades, are inspected to detect fatigue cracks that may be caused by vibratory, mechanical, and/or thermal stresses induced to the engine. Moreover, and for example, some gas turbine engine blades are inspected for deformations such as platform orientation, contour cross-section, bow and twist along a stacking axis, thickness, and/or chord length at given cross-sections. Over time, continued operation of the object with one or more defects may reduce performance of the object and/or lead to object failures, for example, as cracks propagate through the object. Accordingly, detecting defects of the object as early as possible may facilitate increasing the performance of the object and/or reducing object failures.
To facilitate inspecting objects, at least some objects are inspected using a light measurement system that projects a structured light pattern onto a surface of the object. The light measurement system images the structured light pattern reflected from the surface of the object and then analyzes the deformation of the reflected light pattern to calculate the surface features of the object. However, different areas of the object may have different manufacturing tolerances. Accordingly, some areas of the object may require a greater resolution of light projected onto the object than others to obtain enough data to inspect their tolerances. Some known light measurement systems inspect the object at the greatest resolution desired to inspect the object, or in other words, the resolution desired to inspect an area of the object that has the tightest tolerances. However, for areas with looser tolerances, excess data may be obtained from the greater resolution. Such excess date may be filtered or processed down to the resolution desired for the area with looser tolerances, thereby possibly increasing a time and effort of inspecting the object. Other known light measurement systems may inspect object areas of different tolerances with different inspection tools that have different resolutions. However, inspecting different areas of the object with different inspection tools may increase a time of setting up the system and/or object for inspection. Moreover, to merge inspection data for the entire portion of the object inspected, data from multiple sensors may be registered together, which may be time consuming and/or difficult.